[libvirt] [PATCH 2/2] qemu, lxc: Fail explicitly if setting QoS on unsupported vNIC types

[Michal Privoznik]

On 13.01.2015 17:57, Eric Blake wrote:
> On 01/13/2015 09:26 AM, Laine Stump wrote:
> 
>>
>> I do understand Michal's concern. In particular, the network hook script
>> support was put in specifically to allow management apps to support
>> bandwidth management on interface types that libvirt couldn't/didn't
>> directly support. If I recall correctly, the idea is that, although
>> libvirt does nothing with it, the bandwidth info will be in the XML
>> that's passed to the hook script when the interface is brought up, and
>> the hook script can do whatever it likes to setup the bandwidth.
>>
>> Or am I remembering incorrectly.
>>
>> If that functionality is important, then this patch can't go in. If not,
>> then it's a reasonable thing to do.
> 
> In the past, we've had other places where users were actively relying on
> unsupported XML being preserved; when we tightened the schema, a
> complaint was raised that we broke their setups, but we countered that
> their setup was relying on undefined behavior and that we explicitly
> have the namespace-aware annotations that they can use instead to
> guarantee that XML will be preserved and untouched by libvirt.  I'm okay
> with stating that any user relying on this has been relying on
> unsupported behavior, but agree that it is nicer to warn the user rather
> than just silently break things.  Maybe Dan has better advice?
> 

Fair enough, let me respin with VIR_WARN (or is VIR_INFO more appropriate?).

I've pushed the 1/2 btw since it's a code cleanup practically unrelated
to 2/2.

Michal